How do you find (in radians) the exact value of:

Question

tan[pi-(pi/12)]

Answer 1

tan(pi - pi/12),
Factor out pi:
tan(pi(1 - 1/12)),
tan(pi(11/12),
tan(11pi/12),

tan(11pi/12)*180/pi),
tan(165)deg.

Now, I'm not sure what else you want
done. The trig ratios(functions) cannot be written in radians or degrees, because they have no units.
The angles ONLY can be in degrees and radians.